INSECT PEST CONTROL HEAT VAPORIZING MATERIAL

Abstract

There is provided an insect pest control heat vaporizing material in which the end point of vaporization of an effective component can be visually recognized with precision and which has a prolonged period of vaporizing time of the effective component. The insect pest control heat vaporizing material has a carrier supporting a solution of a compound represented by the formula (1): wherein R"^ and R"^ independently indicate a hydrogen atom, a methyl group or a chlorine atom, and R"^ indicates a hydrogen atom, a fluorine atom, a methyl group, a methoxy group or a methoxymethyl group, thereon and being covered by a polyalkylene terephthalate layer having an opening, wherein the carrier is a laminate of a base layer and a "layer modified so as to become transparent when containing an oily liquid" and the polyalkylene terephthalate layer is 0.002 to 0.3 mm thick.

The following specification particularly describes
the nature of this invention and the manner
in which it is to be performed

Or:
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INSECT PEST CONTROL HEAT VAPORIZING MATERIAL
BACKGROUND OF THE INVENTION Field of the Invention
The present invention relates to an insect pest control heat vaporizing material that can be used for a long period of time and a method for controlling insect pests using the same.
Description of the Prior Art
Conventionally, an insect pest control heat vaporizing material (a so-called a mosquito repellent mat) has been used for controlling insect pests such as mosquitoes and flies. Such an insect pest control heat vaporizing material has a fibrous carrier or the like, which supports an insecticidal compound thereon, and is used by heating on a hot plate.
On the other hand, in the field of mothproofing agents for clothing, a performance indicating mothproofing material which is capable of recognizing the end of vaporization of an insecticidal compound visually through discoloration of all or part of the material has been known (for example, JP 4-36123 B and JP 8-73301 B).
In a conventional insect pest control heat vaporizing material, duration of vaporization of an effective

component by heating usually lasts for about 8 hours and therefore^ an insect pest control heat vaporizing material having a longer period of vaporization time of an effective component has been desired. In an insect pest control heat vaporizing material having such a longer period of vaporization time of an effective component, it takes a long time from the start of use till the end of vaporization of an effective component, and therefore, it is especially of importance to precisely recognize the end point of vaporization of the effective component.

SUMMARY OF THE INVENTION
An object of the present invention is to provide an inspect pest control heat vaporizing material in which the end point of vaporization of an effective component can be visually recognized with precision and which has a prolonged period of vaporization time of the effective component.
That is, according to the present invention, there is provided an insect pest control heat vaporizing material which comprises a carrier supporting a solution of a compound represented by the formula (1):
H3C CH3
CH=CR^R^ (1)

wherein R^ and R^ independently indicate a hydrogen atom, a methyl group or a chlorine atom, and R^ indicates a hydrogen atom, a fluorine atom, a methyl group, a luethoxy group or a methoxymethyl group, thereon and being covered by a polyalkylene terephthalate layer having an opening, wherein the carrier is a laminate of a base layer and a "layer modified so as to become transparent when containing an oily liquid" and the polyalkylene terephthalate layer is 0.002 to 0.3 mm thick. The present invention also provides a method for controlling insect pests which comprises the above insect pest control heat vaporizing material is heated at a habitat or an invading place of an insect pest. When the insect pest control heat vaporizing material of the present invention is heated on a hot plate, a period of vaporization time of the effective component is prolonged, and the end point of vaporization of the effective component almost coincides with discoloration of the vaporizing material. More specifically, a period of vaporization time of the effective component is prolonged by the polyalkylene terephthalate cover layer, and the end point of vaporization of the effective component can be recognized visually by change of the "layer modified so as to become transparent when containing an oily liquid" from transparent to opaque owing to vaporization of the oily liquid.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic sectional view of an embodiment of the insect pest control heat vaporizing material of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As seen from Fig. 1, in the insect pest control heat vaporizing material of the present invention, a solution of a compound represented by the formula (1) is supported on a carrier which is a laminate of a base layer 1 and a "layer modified so as to become transparent when containing an oily liquid" 2, and the carrier is covered with a polyalkylene terephthalate layer 3 having an opening, which is 0.002 to 0.3 mm thick.
The compound represented by the formula (1) are known and examples thereof include 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl 3-(1-propenyl)-2,2-
dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-methylbenzyl 3- (1-propenyl)-2,2-
dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluorobenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl 3-(2-methyl-l-propenyl)-2,2-dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-methoxybenzyl 3-(1-propenyl)-2,2-dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-

methoxybenzyl 3-(2-methyl-l-propenyl)-2, 2-dimethylcyclopropanecarboxylate, and 2,3,4,5,6-pentafluorobenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate. These compounds can be produced by known methods.
The compound represented by the formula (1) has stereoisomers owing to the cyclopropane ring and the double bond, and any active isomers or a mixture of isomers can be used-Examples of a solvent used for the solution of the compound represented by the formula (1) include ester type solvents having 15 to 25 carbon atoms such as isopropyl palmitate, dioctyl adipate, dibutyl sebacate, acetyl tributyl citrate, di 2-ethylhexyl maleate and isopropyl myristate•
The amount of the solvent in the solution of the compound represented by the formula (1) used in the insect pest control heat vaporizing material of the present invention is usually 0.1 to 10 parts by weight, preferably 0-5 to 5 parts by weight based on 1 part by weight of the compound represented by the formula (1).
If necessary, the solution of the compound represented by the formula (1) may contain an antioxidant, a synergist, a stabilizer, a perfume, and the like.
Examples of the antioxidant include phenol-type

antioxidants such as dibutyl hydroxytoluene, butyl hydroxyanisole, 2,2-methylenebis(4-methyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-methylphenol, 2-[1- (2-hydroxy-3,5-di-tert-pentylphenyl)ethyl] 4,6-di-tert-pentylphenylacrylate, 3,9-bis[2-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy-l,1-dimethyl]-2,4,8,10-tetraoxaspiro[5•5]undecane, and the like.
The amount of the antioxidant contained in the solution of the compound represented by the formula (1) used in the insect pest control heat vaporizing material of the present invention is usually 0.001 to 1 part by weight, preferably 0.1 to 1 part by weight based on 1 part by weight of the compound represented by the formula (1).
Examples of the synergist include bis-(2,3,3,3-tetrachloropropyl)ether (S-421), N-(2-ethylhexyl)bicyclo[2.2.1]hept-5-en-2,3-dicarboxyimide (MGK
2 64), and a-[2-(2-butoxyethoxy)ethoxy]-4,5-methylenedioxy-2-propyltoluene (PBO).
Examples of the stabilizer include ultraviolet absorbents such as a benzotriazole-type ultraviolet absorbent, a benzophenone-type ultraviolet, and the like.
The carrier used in the insect pest heat vaporizing material of the present invention is a laminate of the base layer and the layer modified so as to become transparent when the solution is contained therein.

The solution can be prepared, for example, by mixing the desired components.
Usually, the base layer is made of a material which can support the compound represented by the formula (1), for example, a fibrous material and/or a porous material. Examples of the fibrous material include paper, cardboard, synthetic fiber mixed paper, a non-woven fabric, a felt like textile, and fabric like inorganic fibers, and examples of the porous material include porous ceramic,
The base layer is preferably colored from the viewpoint of enhanced visual recognizability with respect to the end point of vaporization of a chemical. Such a colored base layer can be prepared, for example, by using a previously colored fibrous material, by impregnating a formed base layer with a colorant, or by applying or printing a colorant on a surface of a base layer.
The base layer is usually in the form of a quadrilateral with a side of about 1 to 6 cm long and is 0.2 to 5 mm thick.
The "layer modified so as to become transparent when containing an oily liquid" is a layer which becomes transparent when containing an oily liquid, while it is opaque when it does not contain the oily liquid. The "layer modified so as to become transparent when containing an oily liquid" is usually porous and has permeability to

the oily liquid. The term "oily liquid" used herein means the solution of the compound represented by the formula (1) itself, or vapor or liquefied vapor formed by the vaporization of the solution.
The "layer modified so as to become transparent when containing an oily liquid" is composed of a mixture of a material which exhibits a low refractive index to light when containing the oily liquid, for example, inorganic pigment such as amorphous silica, kaolin, calcium carbonate, etc., organic pigment such as finely pulverized powder of plastic pigment, etc. , or pulp dust, etc., and a binder. Examples of the binder to be used include vinyl acetate, ethylene-vinyl acetate copolymer, NBR, SBR, and acrylic and other latexes.
The "layer modified so as to become transparent when containing an oily liquid" can be laminated on the base layer by means of coating, printing (screen printing, offset printing, gravure printing, etc.), or the like. The thickness of the "layer modified so as to become transparent when containing an oily liquid" is usually adjusted so that the layer is 4 to 150 g/m , preferably 10 to 60 g/m^.
In case of laminating the "layer modified so as to become transparent when containing an oily liquid" on the base layer by printing, a ratio of the binder to the

material exhibiting a low refractive index to light is usually about 10 to 30 parts by weight of the binder based on 100 parts by weight of the material exhibiting a low refractive index to light. In case of laminating the "layer modified so as to become transparent when containing an oily liquid" on the base layer by coating, a ratio of the binder to the material exhibiting a low refractive index to light is usually about 50 parts by weight based on 100 parts by weight of the material exhibiting a low refractive index to light.
The "layer modified so as to become transparent when containing an oily liquid" may be laminated on the base layer so that it covers the entire surface thereof, or a part of the surface of the base layer in the shape of, for example, indicative letters such as "END", "CHANGE", or the like.
As a method for preparing the above carrier supporting the solution of the compound represented by the formula (1), for example, the carrier is impregnated with the solution of the compound represented by the formula (1). The amount of the solution of the compound represented by the formula (1) supported on the carrier is usually 0.001 to 0.7 g per 1 cm^ of an apparent volume of the carrier in terms of the amount of the compound represented by the formula (1).
In the insect pest control heat vaporizing material of

the present invention, the carrier supporting the solution of the compound represented by the formula (1) is covered by a polyalkylene terephthalate layer having an opening.
Examples of the polyalkylene terephthalate include polyethylene terephthalate and polybutylene terephthalate.
The term ^'covered by" in the present invention includes not only a state where the polyalkylene terephthalate layer covers the surface of a coverage objective (carrier) in close contact with each other, but also a state where the layer covers the surface of a coverage objective (carrier) with a slight clearance (for example, of 1 cm or less) therebetween. The clearance between the carrier and the polyalkylene terephthalate layer is usually, at most, 5 mm or less, preferably 3 mm or less.
The thickness of the polyalkylene terephthalate layer is usually 0.002 to 0.3 mm, preferably 0.01 to 0.1 mm.
In the insect pest control heat vaporizing material of the present invention, the polyalkylene terephthalate layer covering the carrier supporting the solution of the compound represented by the formula (1) has an opening through which an effective component can be vaporized.
Examples of the state where the cover of polyalkylene terephthalate layer has the opening include a state where the cover of polyalkylene terephthalate layer has a cut out

part, a state where the cover of polyalkylene terephthalate layer has many small holes of, for example, about 0.01 to 0.1 mm diameter, and a state where a part of the cover of polyalkylene terephthalate layer is replaced with a layer permeable to vapor of the effective component. The opening in the cover of a polyalkylene terephthalate layer is usually formed only on the side facing the "layer modified so as to become transparent when containing an oily liquid" for convenient use.
The area of the opening formed in the cover of polyalkylene terephthalate layer is usually about 0.01 to 10%, preferably about 0.03 to 3% to an apparent surface area of the carrier supporting the solution of the compound represented by the formula (1).
The carrier supporting the solution of the compound represented by the formula (1) can be covered with the polyalkylene terephthalate layer, for example, by adhering a film or a sheet of the polyalkylene terephthalate to each of the surfaces of the carrier by heat sealing, ultrasonic sealing, or high frequency sealing, with an adhesive, or the like; by forming a polyalkylene terephthalate layer on the surfaces of the carrier by a conventional resin coating technique such as dip coating, spray coating, brushing, or the like; or by placing the carrier in a bag made of a polyalkylene terephthalate and closing the opening of the

bag by heat sealing, ultrasonic sealing, or high frequency sealing, with an adhesive, or the like.
The insect pest control heat vaporizing material of the present invention can be produced, for example, by covering the carrier with a polyalkylene terephthalate film having an opening, or by covering the carrier with a polyalkylene terephthalate film, followed by forming an opening.
Preferably, in the insect pest control heat vaporizing material of the present invention, the opening formed in the polyalkylene terephthalate cover layer is closed with a seal impermeable to the effective component before use and the seal is removed by peeling off, tearing off or cutting off, when the material is used.
Insect pests can be controlled by heating the insect pest control heat vaporizing material of the present
invention at a temperature of 50 to 200°C with a heating device (such as a hot plate) in a habitat or an invading place of an insect pest (such as indoors)
In this case, the insect pest control heat vaporizing material of the present invention is usually heated from the base layer side.
Examples of insect pests that can be controlled by the insect pest control method of the present invention include arthropods such as various kinds of harmful insects, mite

and tick, and the like. Among them, especially, there are flying insect pests including Diptera insect pests, for example, mosquitos (Calicidae) such as common mosquito (Cuiex pipiens pallens), Culex tritaeniorhynchus, etc.; Aedes spp. such as Aedes aegypti, Aedes alhopictus, etc.; Anopheles spp. such as Anopheles sinensis, etc.; midges (Chironomidae); house flies (Muscidae) such as housefly {Musca domestica) , false stablefly {Muscina stabulans), lesser housefly (Fannia canicularis), etc.; Calliphoridae; Sarcophagidae; small fruit flies (Drosophilidae); moth flies (Psychodidae); humpbacked flies (Phoridae); black flies (Simuliidae); Tabanidae; stable flies (Stomoxyidae); sandflies (Ceratopoganidae); and the like.
The following Production Examples and Test Examples further illustrate the present invention in detail but are not to be construed to limit the present invention. Production Example 1
A carrier (20.5 mm x 33 mm x 1.1 mm thick) prepared by laminating a "layer modified so as to become transparent when containing an oily liquid" (obtained by screen printing a mixture of amorphous silica/acrylic latex = 1/0.5 so as to become 15 g/m^ thick) on a part of one surface of a fibrous base layer colored in purple was impregnated with 300 mg of a mixture of 2 parts by weight of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl lR-trans-3-(1-

propenyl(E/Z = 1/8))-2,2-dimethylcyclopropanecarboxylate, 1 part by weight of dibutyl hydroxytoluene and 2 parts by weight of acetyltributyl citrate. The carrier was sandwiched between two polyethylene terephthalate films of
37 mm X 25 mm (a thin polypropylene layer was laminated on one surface of each film for heat sealing), followed by heat sealing along periphery of the polyethylene terephthalate films. Then, the central portion of the polyethylene terephthalate film facing the "layer modified so as to become transparent when containing an oily liquid"
was cut off to form an opening of 3 mm x 3 mm. Thus, the insect pest control heat vaporizing material of the present invention was obtained (hereinafter referred to as the vaporizing material 1 of the present invention). Production Example 2
According to the same manner as that of Production Example 1, the insect pest control heat vaporizing material of the present invention (hereinafter referred to as the vaporizing material 2 of the present invention) was obtained except for using 2,3,4,5,6-pentafluorobenzyl IR-trans-3-(2,2-dichlorovinyl)-2,2-
dimethylcyclopropanecarboxylate instead of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl lR-trans-3-(1-propenyl(E/Z = 1/8))-2,2-dimethylcyclopropanecarboxylate. Production Example 3

According to the same manner as that of Production Example 1, the insect pest control heat vaporizing material of the present invention (hereinafter referred to as the vaporizing material 3 of the present invention) was obtained except for using 2,3,5,6-tetrafluorobenzyl IR-trans-3-(2,2-dichlorovinyl)-2,2-
dimethylcyclopropanecarboxylate instead of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl IR-trans-3-(1-propenyl(E/Z = 1/8))-2,2-dimethylcyclopropanecarboxylate. Production Example 4
According to the same manner as that of Production Example 1, the insect pest control heat vaporizing material of the present invention (hereinafter referred to as the vaporizing material 4 of the present invention) was obtained except for using 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl lR-trans-3-(2-methyl-l-propenyl)-2,2-dimethylcyclopropanecarboxylate instead of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl IR-trans-3-(1-propenyl(E/Z = 1/8))-2,2-dimethylcyclopropanecarboxylate. Comparative Production Example 1
A carrier (20.5 mm x 33 mm x 1.1 mm thick) prepared by laminating a layer modified so as to become transparent when containing the solution (obtained by screen printing a mixture of amorphous silica/acrylic latex = 1/0.5 so as to become 15 g/m^ thick) on a part of one surface of a fibrous

base layer colored in purple was impregnated with 300 mg of a mixture of 2 parts by weight of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl lR-trans-3- (1-propenyl(E/Z = 1/8))-2, 2-dimethylcyclopropanecarboxylate, 1 part by weight of dibutyl hydroxytoluene and 2 parts by weight of acetyltributyl citrate to obtain an insect pest control heat vaporizing material for comparison (hereinafter referred to as the comparative vaporizing material 1). Comparative Production Example 2
According to the same manner as that of Comparative Production Example 1, an insect pest control heat vaporizing material for comparison (hereinafter referred to as the comparative vaporizing material 2) was obtained except for using 2,3,4,5,6-pentafluorobenzyl lR-trans-3-[2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate instead of 2,3,5, 6-tetrafluoro-4-methoxymethylbenzyl IR-trans-3-(l-propenyl(E/Z = l/8))-2,2-dimethy1cyclopropanecarboxylate. Comparative Production Example 3
According to the same manner as that of Comparative Production Example 1, an insect pest control heat vaporizing material for comparison (hereinafter referred to as the comparative vaporizing material 3) was obtained except for using 2,3^5, 6-tetrafluorobenzyl IR-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate

instead of 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl IR-trans-3-(l-propenyl(E/Z = l/8))-2,2-dimethylcyclopropanecarboxylate. Test Example 1
Each of the insect pest control heat vaporizing materials produced Production Examples and Comparative Production Examples was heated on a hot plates at about
170°C to measure time till the "layer modified so as to become transparent when containing an oily liquid" became opaque. The results are shown in Table 1 (repeated three times).

Each of the insect pest control heat vaporizing materials to be tested was heated on a hot plate at about
170°C and a knock-down test of common mosquitos was conducted 144 hours^ 216 hours and 336 hours after the

start of the heating.
Knock-down Test of Common Mosquito
Each of the insect pest control heat vaporizing materials heated on a hot plate was placed at the center portion of a rectangular parallelepiped chamber of 3 m (one
side of the bottom) x 4 m (another side of the bottom) x 2.3 m (height). Immediately after that, about 100 female adult common mosquitos (3 to 5 days after emergence) were released into the chamber. The number of common mosquitos knocked down in the chamber was observed at given time intervals up to 60 minutes after the release to determine a KT 50 value.
After the test, heating of the insect pest control heat vaporizing material tested was continued on the hot plate outside the chamber. The results are shown in Table 2.

The insect pest control heat vaporizing material of the present invention has a prolonged period of vaporizing time of the effective component, and the end point of vaporization of the effective component almost coincides with discoloration of the vaporizing material.

WHAT IS CLAIMED IS:
1. An insect pest control heat vaporizing material
which comprises a carrier supporting a solution of a
compound represented by the following formula (1):

wherein R"^ and R^ independently indicate a hydrogen atom, a methyl group or a chlorine atom, and R^ indicates a hydrogen atom, a fluorine atom, a methyl group, a methoxy group or a methoxymethyl group, thereon and being covered by a polyalkylene terephthalate layer having an opening, wherein the carrier is a laminate of a base layer and a "layer modified so as to become transparent when containing an oily liquid" and the polyalkylene terephthalate layer is 0.002 to 0.3 mm thick.
2. The insect pest control heat vaporizing material
according to claim 1, wherein the compound represented by
the formula (1) is 2,3,5,6-tetrafluoro-4-
methoxymethylbenzyl 3-(1-propenyl)-2,2-
dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-methylbenzyl 3- (1-propenyl)-2,2-
dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluorobenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl 3-{2-methyl-l-